Weather Briefing — La Rochelle → Gibraltar

Issued: Fri 19 Jun 2026 18:15Z · Valid through Tue 23 Jun 2026

Current synoptic setup

A broad Azores High (1025 hPa centred near 35°N 25°W, Chart 1) dominates the eastern Atlantic and extends a ridge over Iberia (1020 hPa). To the north, a deep cut-off low sits south of Iceland (~995 hPa, 552 dam 500 hPa trough overhead) with an associated frontal system draped across the British Isles into the western Approaches. The Bay of Biscay lies in the slack gradient between these features — surface pressure 1015–1020 hPa, light to moderate westerlies (Chart 4 shows 8–14 kt across Biscay, 14–18 kt off Finisterre). Satellite (Chart 8) confirms cloud bands sweeping NW Europe but clear skies over Iberia and the Gulf of Cádiz. The Iceland low tracks slowly ENE; the Azores ridge holds firm.

72-hour outlook

Day 1 (Sat 20 Jun) — Biscay leg. W–WSW 12–18 kt, locally 20 kt in outer Biscay. Seas 1.5–2.0 m from the W (Chart 7: "2" off NW Spain, "1.5" mid-Biscay). No fronts cross the route; cloud and showers stay north of 48°N.

Day 2 (Sun 21 Jun) — Finisterre to off Lisbon. Ridge builds (1025 hPa over Iberia, Chart 2). N–NW 10–15 kt becoming N 15–20 kt as Portuguese trades set in south of Finisterre (Chart 5 shows the yellow 18–22 kt tongue along the Portuguese coast). Seas 1–2 m, NW swell. Excellent sailing conditions.

Day 3 (Mon 22–Tue 23 Jun) — Cape São Vicente to Gibraltar. Ridge axis shifts east, 1020–1025 hPa over Iberia (Chart 3). N–NE 15–20 kt off the Algarve, easing to E 10–15 kt approaching the Strait. Seas <1.5 m. Expect a typical easterly Levanter signature building in the Strait approach.

Top 3 risks to watch

• Portuguese coast acceleration zone. Chart 5 shows 20+ kt squeezing between the Iberian thermal low and the ridge. Uncertainty: peak strength and how far offshore it reaches. Trigger: if buoy/forecast shows >25 kt sustained N of Lisbon, stand 40+ nm offshore.
• Levanter at the Strait. Charts 2–3 show pressure rising over Iberia and weak gradient toward the Med — classic E'ly setup. Uncertainty: onset timing and strength. Trigger: Tarifa forecast >25 kt E, delay Strait entry or stage at Barbate.
• Iceland low's trailing front. Chart 1/2 show the system slow but deepening trough. If it digs south faster than modelled, a front could clip outer Biscay Day 1–2. Trigger: falling pressure at Ouessant + backing wind beyond SW = accelerate south.

Routing considerations

Window is open — depart on the planned schedule. The Azores ridge is the controlling feature and it's strengthening, not eroding. Aim to clear the Chaussée de Sein within 18 hrs to use the W'ly Day 1 before it backs. Favour a rhumbline track to ~45°N 4°W, then offshore of Finisterre (stay outside the TSS, 25 nm off) to exploit the N'ly on Day 2 with the wind on the quarter. South of Cape São Vicente, hug the Algarve coast (10–15 nm) to soften any Levanter build and stage your Strait transit for a slack/west-going tide window. If the Iceland low surprises south, favour the southern semicircle — keep west of any forming low, never let it overtake you to the north.

Advisory only — verify against GRIB updates, Navtex, and OPC bulletins underway.

Weather Briefing — La Rochelle → Gibraltar

Issued: Thu 18 Jun 2026 ~18:40 UTC · Advisory only — verify against fresh GRIBs and own observations underway.

Current synoptic setup

The route is currently under benign control. Chart 1 shows a broad 1020–1025 hPa ridge anchored over the Bay of Biscay, Iberia and the western Med, extending from an Azores cell visible offshore. The dominant feature on the synoptic side is a deep ~1000 hPa low south of Iceland with an associated 500 hPa cold pool (–25°C, 552 dam trough), but its fronts are decaying well north of 50°N before reaching the route. Chart 4 confirms light variable winds across Biscay and off Iberia (mostly 6–12 kt, blue shading), with the stronger 20–28 kt belt confined north of 55°N. Satellite (Chart 8) shows the eastern Atlantic largely cloud-free from Finisterre south — consistent with subsidence under the ridge.

72-hour outlook

Day 1 (Fri 19 Jun) — Biscay crossing. Chart 7 (24 hr) gives N–NE 10–15 kt over outer Biscay, seas 0.5–1.0 m. Light N'ly down the Portuguese coast (Nortada signature, 10–15 kt). No fronts on the route.

Day 2 (Sat 20 Jun) — Finisterre to Lisbon. Chart 2 keeps the 1020 hPa ridge in place; Chart 5 shows N–NE 12–18 kt off NW Iberia, locally 18–22 kt accelerating around Finisterre. Chart 6 (48 hr) shows seas 1–2 m off Portugal, 4 m swell mid-Atlantic at 40°N/30°W (from the Iceland low) — not on route but a long-period NW swell may reach Iberian waters late.

Day 3 (Sun 21 Jun) — São Vicente to Gibraltar. Chart 3 builds a 1025 hPa high over Biscay/France while the Iceland trough digs SE toward Ireland. Expect N 15–20 kt down the Portuguese coast, easing to NE 8–14 kt rounding Cape São Vicente, then E'ly 10–18 kt (Levanter signature) approaching the Strait. No frontal passage on route.

Top 3 risks to watch

• Levanter at Gibraltar. Chart 3's tightening gradient between the Biscay high (1025) and lower pressure over N. Africa hints at E'ly acceleration through the Strait. Uncertain: exact intensity. Trigger: Tarifa observed >25 kt easterly — hold at Barbate or time slack tide.
• Finisterre acceleration. Chart 5 already shows a 20+ kt tongue off NW Spain; ridge strengthening (Chart 3) tightens isobars further. Uncertain: timing of peak. Trigger: CIM buoy >25 kt sustained — stand offshore 30 nm to ease seas off the cape.
• NW swell from Iceland low. Chart 6 shows 4 m at 40°N/30°W. Uncertain: how much reaches the shelf. Trigger: Estaca de Bares swell period >12 s — expect uncomfortable beam seas off Portugal even in light winds.

Routing considerations

Window is open — depart now. The ridge gives a rare 3-day quiet Biscay crossing; delaying risks the next Atlantic trough (Chart 3 shows it digging SW toward Ireland by Mon). Push hard across Biscay in the first 48 hr while winds are light. Stay 30–50 nm off Finisterre to avoid cape acceleration and lee swell. Carry sail south of Lisbon to use the Nortada. Arrive Gibraltar approach early morning to favour lighter Levanter before afternoon strengthening; if Levanter exceeds 25 kt, anchor Barbate and wait for a lull.

Weather Briefing — La Rochelle → Gibraltar

Issued: Wed 17 Jun 2026 ~18:40 UTC | Valid through ~Sat 20 Jun

Current synoptic setup

The North Atlantic is dominated by a deep cut-off low west of Ireland, centred near 52°N 15°W with a core around 995 hPa and a cold pool of –25 °C at 500 hPa (Chart 1). A weaker secondary low sits over Scandinavia (~995 hPa). Critically for the route, the Azores High is well established south and west of Iberia, with a 1020–1025 hPa ridge extending from ~35°N up across Portugal and into the western Med (Charts 1, 3). The Biscay sits in the col between these systems — light gradient at present. Satellite (Chart 8) confirms the frontal cloud band wrapped around the Atlantic low well west of the route; Iberia and the approaches to Gibraltar are largely clear. 10 m winds in Biscay are mostly 8–14 kt from W–NW (Chart 4).

72-hour outlook

• Day 1 (Wed→Thu, La Rochelle → mid-Biscay): WNW–NW 10–16 kt, easing overnight. Seas 1–2 m west-northwesterly swell (Chart 7). No fronts on the route — the Atlantic low's trailing front stays west of 15°W.
• Day 2 (Thu→Fri, Biscay → Finisterre): The Atlantic low retrogrades/weakens toward Greenland (Chart 2), ridge builds. Winds back to N–NW 12–18 kt off Finisterre with the strengthening Portuguese trade (nortada signature on Chart 5). Seas 2–2.5 m NW off Finisterre, dropping to 1.5 m south of 40°N (Chart 6). Fast downwind leg.
• Day 3 (Sat, Portugal coast → Cape São Vicente → Gibraltar): Ridge axis (1025 hPa) sets over Iberia (Chart 3). N–NE 15–20 kt along the Portuguese coast, locally 20–25 kt accelerating around São Vicente. Seas 1–1.5 m. Light/variable in the Gulf of Cádiz; easterly Levanter 15–20 kt likely building in the Strait approaches.

Top 3 risks to watch

• Finisterre/Portuguese coastal acceleration (nortada). Charts 2/5 show tightening isobars along Iberia as the ridge builds. Uncertain how far offshore the 20+ kt band extends. Trigger: observed sustained >22 kt at Cabo Silleiro buoy → stand off 30–40 NM.
• Levanter in the Strait of Gibraltar. Chart 3 shows a pressure gradient building W→E across the Strait by Day 3. Magnitude uncertain at this range. Trigger: Tarifa forecast >25 kt E — time the Strait entry for slack/west-going tide or hold at Barbate.
• Atlantic low re-deepening. Charts 2→3 keep it well west, but ensemble spread at 96 hr is real. Trigger: any southward shift of the 1005 hPa contour below 50°N on the next 00Z run → accelerate the Biscay crossing.

Routing considerations

Window is open — depart within 24 hr. The col-then-ridge sequence gives a textbook downwind delivery. Cross Biscay on a direct rhumb (no need to hedge west); aim to clear 47°N by Day 2 00Z to lock in the NW flow. Favour the eastern (right) semicircle of the receding Atlantic low — that's where you'll be naturally. Offshore standoff of 25–30 NM at Finisterre and São Vicente to ease the cape acceleration. Plan Strait transit for an early-morning slot before Levanter peaks diurnally.

Advisory only — verify against 00Z/12Z updates and local observations underway.

Weather Briefing — La Rochelle → Gibraltar

Issued: Tue 16 Jun 2026, ~20Z | Valid through: Fri 19 Jun

Current synoptic setup

The North Atlantic is dominated by a deep cut-off low centred ~52°N 20°W with a central pressure near 995 hPa and a cold 500 hPa core (-25°C, 552 dam) — clearly visible on Charts 1 and 4, with a tight 10 m wind max of 30–35 kt on its southern flank near 48°N 20°W. A weak ridge at 1015 hPa extends from the Azores across Iberia, keeping the eastern Bay of Biscay and Portuguese coast under light gradient (Chart 4: 5–12 kt). Over the route itself (Biscay → Finisterre → São Vicente) winds are presently NW 8–15 kt, seas 1–2 m (Chart 7). A potential tropical cyclone is flagged off Florida (Chart 7) — far from our route but worth monitoring for later swell. Satellite (Chart 8) confirms the Atlantic low's comma cloud well west of 15°W; Iberia and the Strait are cloud-free.

72-hour outlook

Day 1 (Wed 17 Jun) — Departing La Rochelle: NW 10–15 kt, seas 1–1.5 m in Biscay. The Atlantic low remains stalled near 50°N 25°W; no front reaches the route. Off Finisterre by late day: N 12–18 kt, seas 1.5–2 m. Portuguese trades fill in.

Day 2 (Thu 18 Jun) — Chart 2 shows the low drifting NE toward Ireland, deepening slightly (~1000 hPa). Chart 5: a tongue of 20–25 kt westerlies pushes to ~50°N 15°W but stays well west of Finisterre. On route: N–NNE 15–22 kt (Portuguese nortada filling), seas 2–2.5 m off Cabo da Roca, easing to 1.5 m approaching São Vicente. No frontal passage on the route.

Day 3 (Fri 19 Jun) — Ridge rebuilds over Iberia (Chart 3, 96 h: 1015–1020 hPa Azores High extending E). Expect N 12–18 kt along Portuguese coast, E–ENE 10–15 kt approaching Gibraltar, seas 1–1.5 m. Possible Levanter onset in the Strait by Fri evening.

Top 3 risks to watch

• Atlantic low tracking further south/east than modelled — Charts 2 & 3 keep it north of 48°N, but cut-offs are notoriously poorly handled. Trigger: barometer falling below 1012 hPa west of Finisterre, or swell direction backing to WSW with period >10 s.
• Portuguese nortada acceleration — Chart 5 hints at compression between the Iberian thermal low and Atlantic ridge. Could gust 25–30 kt off Cabo da Roca / São Vicente with steep 2.5–3 m seas. Trigger: sustained >22 kt at Cabo Carvoeiro buoy.
• Levanter in the Strait — Day 3 ridge build (Chart 3) east of Gibraltar favours easterly acceleration. Trigger: Tarifa reporting >20 kt E; if so, time Strait entry for slack/west-going tide.

Routing considerations

Window is OPEN — depart now. The Atlantic low is far enough west that its 30+ kt core never reaches the route in the 72 h window. Aim to clear Finisterre by Thu midday to ride the nortada south on a beam-to-broad reach. Hug within 30–50 nm of the Portuguese coast to stay in the favourable semicircle (eastern side of the Atlantic low = N'lies, following). Time the Strait of Gibraltar entry for Fri morning before Levanter strengthens — verify with Tarifa METAR and a fresh GFS run before committing past São Vicente.

Advisory only — verify against your own observations and updated GRIB/OPC products underway.

Weather Briefing — La Rochelle → Gibraltar

Issued: Mon 15 Jun 2026 20:01 UTC · Advisory only — verify against fresh GRIBs and OPC bulletins underway.

Current synoptic setup

The North Atlantic is dominated by a deep cut-off low centred near 50°N 25°W with a central pressure around 995 hPa (Chart 1), reflected by a sharp 500 hPa cold pool (–25°C, 552 gpdm — Chart 2). A weak ridge (~1015–1020 hPa) extends from the Azores across Iberia, keeping the Bay of Biscay and Portuguese coast in a slack pressure gradient for now. A secondary low sits over Scandinavia (~1005 hPa) but is irrelevant to the route. On Chart 4, the strongest 10 m winds (24–32 kt, yellow/green) are wrapped around the Atlantic low well west of 20°W; Biscay and the Iberian coast show 6–14 kt. Chart 7 (satellite) confirms the spiral cloud signature mid-Atlantic and largely clear skies over Iberia/W. Med.

72-hour outlook

Day 1 (Mon→Tue, Biscay leg): NW–N 10–15 kt across central Biscay, easing toward 5–10 kt near the Spanish shelf. Seas 1–2 m (Chart 6, 24 hr) from NW swell. No frontal passage; ridge dominates. Good motoring/light reaching conditions.

Day 2 (Tue→Wed, Finisterre → off Portugal): Atlantic low elongates SE and deepens slightly (Chart 2, 48 hr — 995 hPa centre near 52°N 20°W). Gradient tightens north of 45°N. On the route: NW 15–20 kt, seas 2–3 m off Finisterre (Chart 5), easing to 1–2 m south of 40°N. Portuguese trades begin to fill in — N'ly 15 kt off Lisbon.

Day 3 (Wed→Thu, São Vicente → Gibraltar): Low retrogrades toward Iceland (Chart 3, 96 hr — 995 hPa near 60°N 25°W); Azores ridge rebuilds across Iberia (~1020 hPa). Route winds: N–NE 15–20 kt off Portugal (Portuguese nortada), backing NE 10–15 kt approaching Cape São Vicente. Gulf of Cádiz to Gibraltar: variable E 10–18 kt; Strait easterly 15–25 kt possible with diurnal acceleration. Seas 1.5–2 m.

Top 3 risks to watch

• Nortada acceleration off Portugal. Charts 2–3 show ridge building behind the low — classic setup for sustained N 20–25 kt with compression along the coast. Charts don't resolve the coastal jet. Trigger: if Lisbon/Sagres METARs show >22 kt sustained, stand offshore 30–50 nm to reduce wind-against-current sea state.

• Levanter in the Strait of Gibraltar. Not visible in these synoptic charts (resolution too coarse), but the rebuilding ridge over Iberia with lower pressure in W. Med favours easterly funnelling. Trigger: Tarifa observations >20 kt E — consider Cádiz layover and time the Strait transit for the lull window (often pre-dawn).

• Atlantic low trajectory uncertainty. Chart 3 shows the 995 hPa system retrograding north — but if it instead tracks SE, Finisterre exposure rises sharply (could see 25–30 kt SW). Trigger: any 12 hr drop in MSLP west of 15°W on subsequent runs — delay the Finisterre rounding.

Routing considerations

Window is open — depart now. The next 48 hr give the cleanest Biscay crossing of the visible forecast period; waiting risks the ridge eroding. Push hard for Finisterre before Day 3 to stay ahead of the nortada strengthening. Round Finisterre with 20+ nm offing to avoid cape acceleration and confused seas. Off Portugal, favour the right (western) side of any approaching trough — you want the N'ly flow on the back side, not the SW'ly ahead. Plan Strait transit for early morning slack to dodge levanter peaks. Keep a Cádiz bail-out option live.

Weather Briefing — La Rochelle → Gibraltar

Issued: Sun 14 Jun 2026 ~18Z | Valid through: Wed 17 Jun

Current synoptic setup

The dominant feature is a deep cut-off low centred near 48°N/25°W with a central MSLP of ~995 hPa and a cold 500 hPa core (-25°C, 552 dam) — clearly visible on Charts 1 and 4, spinning a tight cyclonic wind signature 600–800 nm west of Biscay. A weak ridge (1015–1020 hPa) extends from the Azores across Iberia, keeping the route itself in a slack pressure gradient for now. A secondary low sits over the Baltic (~1005 hPa, Chart 1) but is irrelevant to your track. Steering flow aloft is meridional, so the Atlantic low is slow-moving and drifting ENE toward the British Isles through midweek (Charts 2, 3), gradually pushing its trailing front toward Biscay.

72-hour outlook

Day 1 (Mon 15 Jun) — Biscay / N. Iberia: Light to moderate NW–N 8–14 kt over Biscay (Charts 4, 7), easing to NE 6–10 kt off Finisterre under the ridge. Seas 1–2 m from the NW (Chart 7). No fronts on route. Patchy low cloud/fog risk along the Galician coast.

Day 2 (Tue 16 Jun) — Finisterre to Cape Roca: Atlantic low deepens slightly (Chart 2, ~1000 hPa, still near 48°N/22°W). Gradient tightens over outer Biscay: W–SW 15–22 kt north of 45°N, easing to N 10–15 kt (Portuguese trades) south of Finisterre. Wave heights 2 m on route, 4–5 m in the open Atlantic west of 15°W (Chart 6) — stay east of that.

Day 3 (Wed 17 Jun) — Cape São Vicente to Gibraltar: Ridge rebuilds over Iberia (1015–1020 hPa, Chart 3). Expect classic Portuguese N'lies 12–18 kt, locally 20+ kt accelerating around São Vicente. Approaching the Strait: E'ly Levanter risk as gradient compresses between Iberian ridge and Moroccan thermal low — could see 15–25 kt easterly in the Strait.

Top 3 risks to watch

• Atlantic low tracking SE rather than ENE. Chart 3 keeps it north, but a southerly slip would put Biscay in the warm sector with SW gales. Trigger to re-route: central pressure dropping below 995 hPa or position south of 47°N by Tue 00Z.
• Levanter at Gibraltar. Charts don't resolve the Strait well; the tightening gradient on Chart 3 hints at it. Trigger: Tarifa observations >20 kt E or rising barometer west of the Strait — consider staging in Barbate.
• Finisterre acceleration / NW swell. Chart 6 shows 4–5 m seas not far offshore. Trigger: swell forecast >3 m at 43°N/12°W — stand further inshore on the rhumb line.

Routing considerations

Window is open — depart Mon 15 Jun AM. The cut-off low is far enough west that you can clear Biscay before its trailing front arrives. Aim to be south of 45°N by Tue 12Z to stay ahead of the strengthening SW flow; favour the southern (navigable) semicircle of the Atlantic low by hugging a rhumb-line track, not venturing west of 10°W. Time Cape São Vicente rounding for Wed daylight, and check Tarifa winds 12 h before committing to the Strait.

Advisory — verify against GRIB updates and Navtex underway.